Process for preparing fluoroalkyl-containing organosilicon compounds, and their use

ABSTRACT

Fluoroalkyl organosilicon compounds are prepared by reacting fluoroolefins with organosilicon compounds that contain at least one H--Si group, in the presence of a Pt(0) complex catalyst. Further, fluoroalkylalkoxy organosilicon compounds are prepared by esterifying fluoroalkyl organosilicon compounds. The process proceeds uniformly under mild conditions with high yields and selectivities.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to processes for preparing fluoroalkylorganosilicon compounds by reacting fluorine-containing olefins withorganosilicon compounds in the presence of a platinum catalyst.

2. Discussion of the Background

In recent years, a large number of new applications have been discoveredfor fluoroalkylchlorosilanes and fluoroalkylalkoxysilanes. Thesecompounds are useful as surfactants to modify the surfaces of lenses andoptical fibers or for producing oil-, dirt-, and water-repellentsurfaces, as lubricants, as primers for fluoro resins, as ingredients incosmetic preparations, and as modifiers in fluoro-rubbers and siliconerubbers.

Platinum catalysts are often used for hydrosilylation reactions offluoroolefins to produce the above-mentioned silanes. Typically, thepreferred catalysts are those in which platinum is in the (+4) oxidationstate. However, these Pt(IV) catalyst systems suffer from a number ofdisadvantages.

In many cases, the reactions are required to run under a closed system.JP 02 178 292 A2 discloses the reaction of F₃ C(CF₂)₂ C(CF₃)₂ CH₂ CHCH₂with HSiCl₃ in a blown glass tube in the presence of a H₂ PtCl₆ catalystat a temperature of 100° C. for 3 h with a yield of 83% EP 0 538 061 A2discloses a reaction of CF₃ CF₂ CF₂ OCF(CF₃)CF₂ OCF₂ CF₂ CHCH₂ with CH₃SiHCl₂ in the presence of H₂ PtCl₆ in a steel autoclave at a reactiontemperature of 120° C., with a reaction period of 20 h and a resultingyield of 67%.

At atmospheric pressure, such reactions are relatively lengthy. Forinstance, JP 06 239 872 A2 discloses a reaction time of 48 h for thereaction of C₃ F₇ O CF(CF₃)CF₂ O!₃ CF(CF₃)CHCH₂ with (CH₃)_(3-n)SiHCl_(n) (n=1,2) in the presence of H₂ PtCl₆ at a reaction temperatureof 150° C., resulting in a yield of 88%. WO 94/20442 discloses a yieldof 89% and a reaction period of 50 h for a hydrosilylation reaction, ata reaction temperature of 100° C. in the presence of H₂ PtCl₆.

The reactions may not be stereospecific. WO 94/20442 additionallydiscloses that, for example, in the hydrosilylation reaction of p-CF₃ C₆H₄ CHCH₂ with CH₃ SiHCl₂, isomerization may occur with a concomitantreduction in selectivity. In this case, an 87:13 ratio of β-silylated toα-silylated fluoroolefin is obtained with a yield of 89%.

To raise the selectivity and reactivity, and in some cases to improvethe solubility of the platinum compound, complexing reagents are addedto the platinum catalyst. For example, JP 03 106 889 A2 teaches theaddition of acetone. EP 0 466 958 A1 discloses isopropanol as anadditive, while EP 0 573 282 A1 discloses the use of H₂ PtCl₆ in2-ethylhexanal. It is also known to add m-xylene hexafluoride to the Ptcatalyst (EP 0 573 282 A1). However, in all of these examples, the costand complexity of preparation are considerable.

In general, none of the above-mentioned catalyst systems aresufficiently reactive or selective, with the result that, from aneconomic standpoint, such processes are of little interest for thepreparation of fluoroalkyl-containing organosilicon compounds.

SUMMARY OF THE INVENTION

One object of the present invention is to provide a process forpreparing fluoroalkyl organosilicon compounds simply and economically.

Another object of the present invention is to provide a process forpreparing fluoroalkyl organosilicon compounds under mild reactionconditions with high yields and high selectivity.

Another object of the present invention is to provide a process forpreparing fluoroalkyl organosilicon compounds using KARSTEDT catalysts.

Another object of the present invention is to provide a process whichproceeds uniformly under atmospheric pressure and at low temperatures.

Another object of the present invention is to provide a process whichdoes not require an excess amount of organosilicon reactant, therebyminimizing the proportion of byproducts that require separation anddisposal.

Another object of the present invention is to provide a process forpreparing fluoroalkyl organosilicon compounds in which unwantedisomerization is reduced or eliminated.

Another object of the present invention is to provide a process forpreparing fluoroalkylalkoxy organosilicon compounds.

Another object of the present invention provides for surface-treatingagents for enhancing the surface of plastics, glass, metals, ceramicsand stone; textile auxiliaries; and architectural preservativepreparations which contain fluoroalkyl organosilicon compounds producedby the process.

These and other objects of the present invention have been achieved byreacting, in the presence of a Pt(0) complex catalyst, at least onefluoroolefin with at least one organosilicon compound that contains atleast one H--Si group.

The first embodiment of the invention relates to a process for preparingfluoroalkyl organosilicon compounds, which includes:

reacting, in the presence of a Pt(0) complex catalyst,

at least one fluoroolefin with

at least one organosilicon compound that contains at least one H--Sigroup.

The second embodiment of the invention relates to a process forpreparing a fluoroalkylalkoxy organosilicon compound, which includes:

reacting, in the presence of a Pt(0) complex catalyst,

at least one fluoroolefin with

at least one organosilicon compound that contains at least one H--Sigroup; and

esterifying with an alcohol.

The third embodiment of the invention relates to a fluoroalkylorganosilicon compound prepared by a process which includes:

reacting, in the presence of a Pt(0) complex catalyst,

at least one fluoroolefin with

at least one organosilicon compound that contains at least one H--Sigroup.

By means of the present invention, fluoroalkyl and fluoroalkylalkyoxyorganosilicon compounds can be produced with yields of up to 99%.Heretofore, it was completely unexpected that a process of reacting atleast one fluoroolefin with at least one organosilicon compound thatcontains at least one H--Si group, in the presence of a Pt(0) complexcatalyst, would proceed so uniformly, under such mild conditions, andwith such improved reactivity, selectivity, and yield.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Other features of the invention will become apparent in the course ofthe following descriptions of exemplary embodiments which are given forillustration of the invention and are not intended to be limitingthereof

In the present process, it is preferred to employ a Pt(0) complexcatalyst of the KARSTEDT type. More preferably, the KARSTEDT catalyst isselected from the group consisting of bis1,3-bis(eta-2-ethenyl)-1,1,3,3-tetramethyldisiloxane!platinum(0),triphenylphosphine-1,3-bis(eta-2-ethenyl)-1,1,3,3-tetramethyldisiloxane!platinum(0) and2,4,6,8-tetraethenyl-2,4,6,8-tetramethylcyclotetrasiloxane platinum(0).Preferred KARSTEDT catalysts are those which contain 0.01-20% by weightof platinum, based on the weight of the catalyst, preferably 0.1-10% byweight of platinum and, more preferably 0.5-5% by weight of platinumThese ranges include all specific values and subranges therebetween. Thecatalyst system can be dissolved in an inert solvent. Suitable solventsare xylene (o-, m-, and p-) and toluene. Other inert solvents may beused that are known in the art having boiling points between 100°-200°C., preferably 110°-160° C., and more preferably 110°-145° C. Theseranges include all specific values and subranges therebetween.

DE-A 1 941 411, FR-A 2 474 890 and U.S. Pat. No. 3,775,452 discloseplatinum catalysts of the KARSTEDT type, the contents of each are herebyincorporated by reference.

The present reaction is preferably carried out employing at least onefluoroolefin of the general formula (I)

    R.sup.1 YCH═CH.sub.2                                   (I)

in which

R¹ is a mono-, oligo-, or perfluorinated alkyl group having 1 to 20,preferably 1 to 9 carbon atoms or a mono-, oligo-, or perfluorinatedaryl group having 6 to 10, preferably 6 carbon atoms and Y is a --CH₂--, --O-- or --S-- group. Examples are --CF₃ (CF₂)_(n) CHCH₂ wheren=3,5,7 and 9, HCF₂ CF₂ OCH₂ CHCH₂, and R_(f) CH₂ CH₂ O(CO)(C(CH₃))CH₂where R_(f) =C_(n) F_(2n+1), in which n=2 to 18.

The organosilicon compound that contains at least one H--Si group ispreferably a hydrosilane of the general formula (II):

    H.sub.(4-a-b) SiR.sup.2.sub.a X.sub.b                      (II)

in which

R₂ is identical or different alkyl groups of 1 to 20 carbon atoms,preferably methyl or ethyl, or aryl groups having 6 to 10 carbon atoms,preferably phenyl,

X is a Cl or Br, and

a=0, 1, 2, or 3 and b=0, 1, 2 or 3 where 1≦(a+b)≦3;

or

a disiloxane of the general formula (III):

    R.sup.2.sub.a X.sub.b H.sub.(3-a-b) SiOSiH.sub.(3-a-b) R.sup.2.sub.a X.sub.b(III)

in which

R² is identical or different alkyl groups of 1 to 20 carbon atoms,preferably methyl or ethyl, or aryl groups having 6 to 10 carbon atoms,preferably phenyl,

X is independently in each case a Cl or Br, and

a=0, 1 or 2, and b=0, 1, or 2 where 1≦(a+b)≦2;

or

a cyclic siloxane of the general formula (IV):

    (R.sup.2.sub.a X.sub.b SiO).sub.x (R.sup.2.sub.s X.sub.t H.sub.(2-s-t) SiO).sub.y                                                (IV)

in which

R² is identical or different alkyl groups of 1 to 20 carbon atoms,preferably methyl or ethyl, or aryl groups having 6 to 10 carbon atoms,preferably phenyl,

X is independently in each case a Cl or Br,

a=0, 1, or 2 and b=0, 1, or 2 where (a+b)=2, and

x adopts a value from 0 to 5,

s=0 or 1 and t=0 or 1 where 0≦(s+t)≦1, and

y adopts a value from 1 to 5 where 3≦(x+y)≦5;

or

linear polysiloxane mixtures of the general formula (V)

    R.sup.2.sub.a X.sub.b SiO(R.sup.2.sub.f X.sub.i SiO).sub.q (R.sup.2.sub.s X.sub.t H.sub.(2-s-t) SiO).sub.r SiR.sup.2.sub.a X.sub.b  (V)

where

R² identical or different alkyl groups of 1 to 20 carbon atoms,preferably methyl or ethyl, or aryl groups having 6 to 10 carbon atoms,preferably phenyl,

X is independently in each case a Cl or Br,

a=0, 1, 2, or 3 and b=0, 1, 2, or 3 where (a+b)=3, f=0, 1 or 2 and i=0,1 or 2 where (f+i)=2, and

q≧0, s=0 or 1 and t=0 or 1 where 0≦(s+t)≦1 and r≧1 where50≦(q+r)≦50,000, preferably 5,000 to 10,000.

The organosilicon compound that contains at least one H--Si group ismore preferably HSiCl₃, HSiCH₃ Cl₂ or HSi(CH₃)₂ Cl.

In the starting mixture, the total amount of platinum relative to thetotal amount of the fluoroolefin is preferably in a weight ratio of1:100 to 1:100,000, preferably in a ratio of 1:1,000 to 1:30,000 andmost preferably in a ratio of 1:5,000 to 1:20,000. More preferably, inthe starting mixture, the total amount of the platinum relative to thetotal amount of the fluoroolefin having the general formula (I) ispreferably in a weight ratio of 1:100 to 1:100,000, preferably in aratio of 1:1,000 to 1:30,000 and most preferably in a ratio of 1:5,000to 1:20,000. These ranges include all specific values and subrangestherebetween.

The fluoroolefin is preferably first charged into a vessel, which can beboth heated and cooled, has a stirring device and reflux condenser, andequipped to run under nitrogen, argon, or another inert atmosphere. ThePt(0) catalyst, preferably dissolved in a solvent, is then added.

The organosilicon compound that contains at least one H--Si group canthen be supplied to the reaction vessel by way of a metering device.

The addition of the organosilicon compound that contains at least oneH--Si group to the fluoroolefin is generally commenced at roomtemperature. The heat produced during this addition may be completelysufficient to drive the reaction. Alternatively, heat may be applied tothe reaction from an outside source. Since a heat source is notnecessarily required, however, and the reaction proceeds even underatmospheric pressure, the expenditure on apparatus is generally low.Because the reactivity and selectivity of the process is high, an excessof the organosilicon compound that contains at least one H--Si group isgenerally not required, thus also minimizing the proportion ofbyproducts and reactants which may remain, and require disposal, afterthe process has been carried out.

When conducting the present process on a laboratory scale (500 ml), theaddition of the organosilicon compound that contains at least one H--Sigroup generally takes place over a period of 20 to 120 minutes,preferably from 30 to 60 minutes. These ranges include all specificvalues and subranges therebetween. The reaction mixture may be stirredduring the addition of the organosilicon compound that has at least oneH--Si group, which stirring may be continued after completion of theaddition. In general, stirring is continued for 1 to 5 h, preferably 1to 3 h, more preferably 1 to 1.5 h. These ranges include all specificvalues and subranges therebetween. The addition time and stirring timemay be scaled up as necessary to effect the process on a larger scale.

The reaction is preferably carried out at a temperature in the range of10° to 200° C., more preferably 20° to 150° C. The pressure is in therange of 1 to 50 bar abs., preferably 1 to 10 bar abs. These rangesinclude all specific values and subranges therebetween.

After the reaction is complete, the fluoroalkyl organosilicon compoundis recovered from the reaction mixture. Preferably, the reaction mixturecan be worked up by distillation.

It is thus possible, simply and economically and in accordance with theprocess, to prepare, for example,3,3,4,4,5,5,6,6,7,7,8,8,9,9,10,10,10-heptadecafluorooctyltrichlorosilane,3,3,4,4,5,5,6,6,7,7,8,8,8-tridecafluorooctylmethyldichlorosilane and3-(1,1,2,2-tetrafluoroethoxy)propyltrichlorosilane.

The process offers the advantage of synthesizing fluoroalkylorganosilicon compounds under mild reaction conditions, with high yieldsand high selectivity, and using low concentrations of catalyst. In theprocess, there are generally no instances either of isomerization of thedouble bond in the course of the addition reaction with, for example,trichlorosilanes, alkylchlorosilanes or arylchlorosilanes, or ofisomerization of the fluoroalkyl radicals. Further advantages of thepresent process are the short reaction times and the uniform progressionof the reaction.

Fluoroalkyl organosilicon compounds that contain at least one Cl--Sigroup or Br--Si group that may be obtained by the present process can beesterified with an alcohol to give the corresponding alkoxy-Sicompounds. Preferred alcohols include methanol, ethanol, n-propanol,i-propanol, n-butanol, i-butanol, t-butanol or 2-methoxyethanol. In thiscase, the reaction mixture that contains the fluoroalkyl organosiliconcompound can be used without further purification as the startingmaterial for the esterification of the Cl--Si or Br--Si groups with analcohol. The esterification step proceeds uniformly. The separation ofany remaining highly volatile fractions may be effected by simpledistillation, giving fluoroalkylalkoxy organosilicon compounds with apurity of from 98.5 to 99.9% by area GC-TCD (=percent of the integratedpeak area in the chromatogram with detection by thermal conductivitydetector), for example,3,3,4,4,5,5,6,6,7,7,8,8,8-tridecafluorooctyltrichlorosilane.

The present invention, therefore, also provides a process for preparingfluoroalkylalkoxy organosilicon compounds of the general formula (VI):

    R.sup.1 -Y-(CH.sub.2).sub.2 SiH.sub.a R.sup.2.sub.b (OR.sup.3).sub.(3-a-b)(VI)

in which

R¹ is a mono-, oligo-, or perfluorinated alkyl group of 1 to 20,preferably 1 to 9 carbon atoms or a mono-, oligo-, or perfluorinatedaryl group having 6 to 10 carbon atoms, preferably CF₃ (CF₂)₇ --, CF₃(C₆ H₄)--, C₆ F₅ --, R_(f) CH₂ CH₂ (CO)--(R_(f) =C_(n) F_(2n+1) wheren=2 to 18), and Y is a CH₂, O or S group.

R² is an alkyl group of 1 to 20, preferably 1 to 8 carbon atoms or anaryl group having 6 to 10 carbon atoms,

R³ is an alkyl group of 1 to 20, preferably 1 to 8 carbon atoms or anaryl group having 6 to 10 carbon atoms, and

a=0, 1 or 2and b=0, 1 or 2where(a+b)≦2,

which includes reacting a fluoroalkyl organosilicon compound thatcontains at least one Cl--Si or Br--Si group with a monohydric alcoholand recovering the fluoroalkylalkoxy organosilicon compound of thegeneral formula (VI) from the reaction mixture.

EXAMPLES

Having generally described this invention, a further understanding canbe obtained by reference to certain specific examples which are providedherein for purposes of illustration only and are not intended to belimiting unless otherwise specified.

Example 1

126 g (0.8 mol) of 1,1,2,2-tetrafluoroethyl allyl ether are chargedunder an N₂ atmosphere to a 500 ml three-necked glass flask providedwith top-mounted water condenser, magnetic stirrer, thermometer anddropping funnel, and 0.4 g of CPC 072(Pt(0)-divinyltetramethyldisiloxane in xylene; concentration Pt:1,1,2,2-tetrafluoroethyl allyl ether 1:20,000) are added. 108 g (0.8mol) of trichlorosilane are added dropwise at room temperature and withstirring over a period of 80 minutes. The immediately ensuing reactionis exothermic, the temperature rising to 110° C. After the end of theaddition, the reaction mixture is stirred for 1 h more and then analyzedby GC. After subsequent distillative purification over a short-pathcolumn, 225 g (0.77 mol) of3-(1,1,2,2-tetrafluoroethoxy)propyltrichlorosilane are obtained (yield-.96%, purity: >98 area % GC-TCD).

Example 2

192 g (0.55 mol) of 3,3,4,4,5,5,6,6,7,7,8,8,8-tridecafluorooctene arecharged under an N₂ atmosphere to a 500 ml three-necked glass flaskprovided with top mounted water condenser, magnetic stirrer, thermometerand dropping funnel, and 0.3 g of CPC 072(Pt(0)-divinyltetramethyidisiloxane in xylene, concentration Pt:3,3,4,4,5,5,6,6,7,7,8,8,8-tridecafluorooctene=1:20,000) are added. 80 g(0.59 mol) of trichlorosilane are added dropwise at room temperature andwith stirring over a period of 85 minutes. The immediately ensuingreaction is exothermic, the temperature rising to 115° C. After the endof the addition, the reaction mixture is stirred for 1.5 h more and thenanalyzed by GC. After subsequent distillative purification over ashort-path column, 262 g (0.54 mol) of3,3,4,4,5,5,6,6,7,7,8,8,8-tridecafluorooctyltrichlorosilane are obtained(yield: 99%, purity: >97 area % GC-TCD).

Example 3

123 g (0.5 mol) of 3,3,4,4,5,5,6,6,6-nonafluorohexene and 76 g (0.5 mol)of trichlorosilane together with 0.34 g of CPC 072(Pt(0)-divinyltetramethyldisiloxane in xylene; concentrationPt:3,3,4,4,5,5,6,6,6-nonafluorohexene=1:20,000) are charged to a 250 mllaboratory steel autoclave. The autoclave is closed and heated to 140°C. in an oil bath over 70 minutes. The exothermic reaction begins afterabout 8 minutes, the reaction mixture rising to 165° C. It issubsequently cooled, the reactor is emptied, and short-path distillationgives 176 g (0.46 mol) of3,3,4,4,5,5,6,6,6-nonafluorohexyltrichlorosilane (yield: 90%,purity: >98 area % GC-TCD).

Example 4

544 g (1.83 mol) of 3-(1,1,2,2-tetrafluoroethoxy)propyltrichlorosilaneare charged to a 1,000 ml three-necked glass flask provided withtop-mounted water condenser, magnetic stirrer, thermometer and droppingfunnel, and 256 g (5.57 mol) of ethanol are added dropwise over 6.5 hwith stirring. The reaction proceeds exothermically, the reactionmixture rising to 110° C. 165 g of NaOEt solution (21% in ethanol) arethen added over a further 90 minutes. After cooling, the NaCl formed isfiltered off and the filtrate is distilled over a short-path column. 519g (1.61 mol) of 3-(1,1,2,2-tetrafluoroethoxy)propyltriethoxysilane areobtained (yield: 90%, purity: >98 area % GCTCD).

The entire contents of German patent application 196 44 561.2, filedOct. 26, 1996, are hereby incorporated by reference.

Obviously, numerous modifications and variations of the presentinvention are possible in light of the above teachings. It is thereforeto be understood that within the scope of the appended claims, theinvention may be practiced otherwise than as specifically describedherein.

What is claimed as new and desired to be secured by Letters Patent ofthe United States is:
 1. A process for preparing fluoroalkylorganosilicon compounds comprising:reacting, in the presence of a Pt(0)complex catalyst, at least one fluoroolefin with at least oneorganosilicon compound that contains at least one H--Si group.
 2. Theprocess as claimed in claim 1, wherein said Pt(0) complex catalystcomprises a KARSTEDT catalyst.
 3. The process as claimed in claim 1,wherein said Pt(0) complex catalyst contains 0.01 to 20% by weight ofplatinum.
 4. The process as claimed in claim 2, wherein said KARSTEDTcatalyst is selected from the group consisting of bis1,3-bis(eta-2-ethenyl)- 1,1,3,3-tetramethyidisiloxane!platinum(0),triphenylphosphine-1,3bis(eta-2-ethenyl)-1,1,3,3-tetramethyldisiloxane!platinum(0) and2,4,6,8-tetraethenyl-2,4,6,8-tetramethylcyclotetrasiloxaneplatinum(0).5. The process as claimed in claim 1, wherein said fluoroolefincomprises a fluorolefin having the general formula (I):

    R.sup.1 YCH═CH.sub.2                                   (I)

wherein R¹ is a mono-, oligo-, or perfluorinated alkyl group having 1 to20 carbon atoms or a mono-, oligo-, or perfluorinated aryl group having6 to 10 carbon atoms, and Y is a --CH₂ --, --O-- or --S-- group.
 6. Theprocess as claimed in claim 1, wherein said organosilicon compound thatcontains at least one H--Si group comprises a hydrosilane having thegeneral formula (II):

    H.sub.(4-a-b) SiR.sup.2.sub.a X.sub.b                      (II)

wherein R² is identical or different alkyl groups having 1 to 20 carbonatoms or aryl groups having 6 to 10 carbon atoms, X is independently Clor Br, and a=0, 1, 2, or 3 and b=0, 1, 2, or 3 wherein 1≦(a+b)≦3.
 7. Theprocess as claimed in claim 1, wherein said organosilicon compound thatcontains at least one H--Si group comprises a disiloxane having thegeneral formula (III):

    R.sup.2.sub.a X.sub.b H.sub.(3-a-b) SiOSiH.sub.(3-a-b) R.sup.2.sub.a X.sub.b(III)

wherein R² is identical or different alkyl groups of 1 to 20 carbonatoms or aryl groups having 6 to 10 carbon atoms, X is independently Clor Br, and a=0, 1, or 2 and b=0, 1, or 2 wherein 1≦(a+b)≦2.
 8. Theprocess as claimed in claim 1, wherein organosilicon compound thatcontains at least one H--Si group comprises a cyclic siloxane having thegeneral formula (IV):

    (R.sup.2.sub.a X.sub.b SiO).sub.x (R.sup.2.sub.s X.sub.t H.sub.(2-s-t) SiO).sub.y                                                (IV)

wherein R² is identical or different alkyl groups of 1 to 20 carbonatoms or aryl groups having 6 to 10 carbon atoms, X is independently Clor Br, a=0, 1, or 2 and b=0, 1, or 2 where (a+b)=2, and x is 0 to 5, s=0or 1 and t=0 or 1 where 0≦(s+t)≦1, and y is 1 to 5 wherein 3 ≦(x+y)≦5.9. The process as claimed in claim 1, wherein said organosiliconcompound that has at least one H--Si group comprises a linearpolysiloxane having the general formula (V):

    R.sup.2.sub.a X.sub.b SiO(R.sup.2.sub.f X.sub.i SiO).sub.q (R.sup.2.sub.s X.sub.t H.sub.(2-s-t) SiO).sub.r SiR.sup.2.sub.a X.sub.b  (V)

wherein R² is identical or different alkyl groups of 1 to 20 carbonatoms or aryl groups having 6 to 10 carbon atoms, X is Cl or Br, a=0, 1,2, or 3 and b=0, 1, 2, or 3 wherein (a+b)=3, f=0, 1, or 2 and i=0, 1, or2 wherein (f+i)=2, and q≧0, s=0 or 1 and t=0 or 1 wherein 0 ≦(s+t)≦1 andr≧1 wherein 50≦(q+r)≦50,000.
 10. The process as claimed in claim 1,wherein the weight ratio of the total amount of platinum to the totalamount of said fluoroolefin is 1:100 to 1:100,000.
 11. The process asclaimed in claim 1, wherein the reaction is carried out at a temperatureof 10° to 200° C.
 12. The process as claimed in claim 1, wherein thereaction is carried out at a pressure of 1 to 50 bar abs.
 13. Theprocess as claimed in claim 1, further comprising esterifying theobtained fluoroalkyl organosilicon compounds with an alcohol selectedfrom the group consisting of methanol, ethanol, n-propinol, i-propanol,n-butanol, i-butanol, t-butanol, 2-methoxyethanol, and mixtures thereof.14. The process as claimed in claim 1, further comprising purifying theobtained fluoroalkyl organosilicon compounds by distillation.
 15. Aprocess for preparing a fluoroalkylalkoxy organosilicon compound havingthe general formula (VI):

    R.sup.1 -Y-(CH.sub.2).sub.2 SiH.sub.a R.sup.2.sub.b (OR.sup.3).sub.(3-a-b)(VI)

wherein R¹ is a mono-, oligo-, or perfluorinated alkyl group having 1 to20 carbon atoms or a mono-, oligo-, or perfluorinated aryl group having6 to 10 carbon atoms, and Y is a --CH₂ --, --O--, or --S-- group, R² isidentical or different alkyl groups having 1 to 20 carbon atoms or arylgroups having 6 to 10 carbon atoms, R³ is an alkyl group having 1 to 20carbon atoms or an aryl group having 6 to 10 carbon atoms, and a=0, 1,or 2 and b=0, 1, or 2 wherein (a+b)≦2, comprising the steps of:reacting,in the presence of a Pt(0) complex catalyst, at least one fluoroolefinwith at least one organosilicon compound that contains at least oneH--Si group; esterifying with an alcohol; and purifying by distillationa fluoroalkylalkoxy organosilicon compound having the general formula(VI):

    R.sup.1 -Y-(CH.sub.2).sub.2 SiH.sub.a R.sup.2.sub.b (OR.sup.3).sub.(3-a-b)(VI)

wherein R¹ is a mono-, oligo-, or perfluorinated alkyl group having 1 to20 carbon atoms or a mono-, oligo-, or perfluoriniated aryl group having6 to 10 carbon atoms, and Y is a --CH₂ --, --O--, or --S-- group, R² isidentical or different alkyl groups having 1 to 20 carbon atoms or arylgroups having 6 to 10 carbon atoms, R³ is an alkyl group having 1 to 20carbon atoms or an aryl group having 6 to 10 carbon atoms, and a=0, 1,or 2 and b=0, 1, or 2 wherein (a+b)≦2.
 16. The process as claimed inclaim 15, wherein said Pt(0) complex catalyst comprises a KARSTEDTcatalyst.
 17. The process is claimed in claim 15, wherein saidfluoroolefin comprises a fluoroolefin having the general formula (1):

    R.sup.1 YCH═CH.sub.2                                   (I)

wherein R¹ is a mono-, oligo-, or perfluorinated alkyl group having 1 to20 carbon atoms or a mono-, oligo-, or perfluorinated aryl group having6 to 10 carbon atoms, and Y is a --CH₂ --, --O-- or --S-- group.
 18. Theprocess as claimed in claim 15, wherein said organosilicon compound thatcontains at least one H--Si group comprises a hydrosilane having thegeneral formula (II):

    H.sub.(4-a-b) SiR.sup.2.sub.a X.sub.b                      (II)

wherein R² is identical or different alkyl groups having 1 to 20 carbonatoms or aryl groups having 6 to 10 carbon atoms, X is independently Clor Br, and a=0, 1, 2, or 3 and b=0, 1, 2, or 3 wherein 1≦(a+b)≦3.
 19. Afluoroalkyl organosilicon compound produced by a processcomprising:reacting, in the presence of a Pt(0) complex catalyst, atleast one fluoroolefin with at least one organosilicon compound thatcontains at least one H--Si group.
 20. A surface-treating agent,comprising the fluoroalkyl organosilicon compound prepared by theprocess of claim 18.